1. Temperature diagnostic to identify high risk areas and optimize Legionella pneumophila surveillance in hot water distribution systems
- Author
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Dominique Charron, Patrick Dolcé, Emilie Bédard, Eric Déziel, Philippe Cantin, Céline Laferrière, Cindy Lalancette, Stéphanie Fey, Michèle Prévost, École Polytechinique, département de génie civil, Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS) - Réseau International des Instituts Pasteur - Institut Armand Frappier, Centre d'Expertise en Analyse Environnementale du Quebec (CEAEQ), Centre d'Expertise en Analyse Environnementale du Quebec, Centre Hospitalier Régional de Rimouski, CHU Sainte Justine [Montréal], This study was supported by the partners of the NSERC Industrial Chair on Drinking Water. The authors would like tothank Chair staff especially Yves Fontaine and Jacinthe Mailly, participating HCFs, especially Christiane Parent, Maurice Isabel, Stephane Boucher, Jean-Raymond Felix, and Manuela Villion from CEAEQfor her help with microbiological analyses. Eric DDieziel holds a Canada Research Chair., and Réseau International des Instituts Pasteur (RIIP)-Institut National de la Recherche Scientifique [Québec] (INRS)
- Subjects
Hot Temperature ,[SDV]Life Sciences [q-bio] ,Water supply ,MESH: Legionnaires' Disease ,MESH: Maintenance and Engineering, Hospital ,Legionella pneumophila ,Thermal control ,Distribution system ,MESH: Disinfection ,[SHS.ENVIR] Humanities and Social Sciences/Environmental studies ,MESH: Water Supply ,Waste Management and Disposal ,Water Science and Technology ,MESH: Sanitary Engineering ,Waste management ,Ecological Modeling ,Pollution ,6. Clean water ,3. Good health ,[SDV] Life Sciences [q-bio] ,Legionnaires' disease ,Legionnaires' Disease ,Water Microbiology ,Risk assessment ,Viable but not culturable (VBNC) ,Environmental Engineering ,Legionella ,Sanitary engineering ,MESH: Hot Temperature ,Biology ,Culturability ,Water Supply ,Temperature profile ,medicine ,Civil and Structural Engineering ,business.industry ,Environmental engineering ,Premise plumbing ,biology.organism_classification ,medicine.disease ,MESH: Legionella pneumophila ,[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,Disinfection ,MESH: Water Microbiology ,[SHS.ENVIR]Humanities and Social Sciences/Environmental studies ,Sanitary Engineering ,[SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,Maintenance and Engineering, Hospital ,business - Abstract
International audience; Legionella pneumophila is frequently detected in hot water distribution systems and thermal control is a common measure implemented by health care facilities. A risk assessment based on water temperature profiling and temperature distribution within the network is proposed, to guide effective monitoring strategies and allow the identification of high risk areas. Temperature and heat loss at control points (water heater, recirculation, representative points-of-use) were monitored in various sections of five health care facilities hot water distribution systems and results used to develop a temperature-based risk assessment tool. Detailed investigations show that defective return valves in faucets can cause widespread temperature losses because of hot and cold water mixing. Systems in which water temperature coming out of the water heaters was kept consistently above 60 °C and maintained above 55 °C across the network were negative for Legionella by culture or qPCR. For systems not meeting these temperature criteria, risk areas for L. pneumophila were identified using temperature profiling and system's characterization; higher risk was confirmed by more frequent microbiological detection by culture and qPCR. Results confirmed that maintaining sufficiently high temperatures within hot water distribution systems suppressed L. pneumophila culturability. However, the risk remains as shown by the persistence of L. pneumophila by qPCR.
- Published
- 2015
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